Stock-based Compensation (Tables)
 6 Months Ended
Jan. 31, 2016
Stock-based Compensation  
Schedule Of Stock Option Activity [Table Text Block]
The following table summarizes stock option activity as of January 31, 2016:
 
Options
 
Weighted-
Average
Exercise
Price
 
Weighted-
Average
Remaining
Contractual
Life
 
Aggregate
Intrinsic
Value
 
(Options in
thousands)
 
 
 
(In years)
 
 
Outstanding at August 2, 2015
74

 
$
29.91

 
 
 
 
Granted
711

 
$
50.21

 
 
 
 
Exercised
(74
)
 
$
29.91

 
 
 
 
Terminated
—

 
$
—

 
 
 
 
Outstanding at January 31, 2016
711

 
$
50.21

 
9.7

 
$
4

Exercisable at January 31, 2016
—

 
$
—

 
—

 
$
—
Schedule of Share-based Payment Award, Assumptions [Table Text Block]
 
2016
Risk-free interest rate
1.68%
Expected dividend yield
2.46%
Expected volatility
18.35%
Expected term
6 years
Time Lapse EPS, Strategic Performance And Special Performance Restricted Stock Units [Member]  
Stock-based Compensation  
Schedule of other Share-based awards Activity [Table Text Block]
The following table summarizes time-lapse restricted stock units, EPS performance restricted stock units, strategic performance restricted stock units and special performance restricted stock units as of January 31, 2016:
 
Units
 
Weighted-
Average
Grant-Date
Fair Value
 
(Restricted stock
units in thousands)
 
 
Nonvested at August 2, 2015
2,410

 
$
41.40

Granted
672

 
$
50.00

Vested
(800
)
 
$
39.31

Forfeited
(171
)
 
$
43.45

Nonvested at January 31, 2016
2,111

 
$
44.77
TSR Performance Restricted Stock/Units [Member]  
Stock-based Compensation  
Schedule of other Share-based awards Activity [Table Text Block]
The following table summarizes TSR performance restricted stock units as of January 31, 2016:
 
Units
 
Weighted-
Average
Grant-Date
Fair Value
 
(Restricted stock
units in thousands)
 
 
Nonvested at August 2, 2015
1,579

 
$
40.75

Granted
682

 
$
62.44

Vested
(438
)
 
$
39.76

Forfeited
(126
)
 
$
46.36

Nonvested at January 31, 2016
1,697

 
$
49.30
Schedule of Share-based Payment Award, Assumptions [Table Text Block]
We estimated the fair value of TSR performance restricted stock units at the grant date using a Monte Carlo simulation. Assumptions used in the Monte Carlo simulation were as follows:
 
2016
 
2015
Risk-free interest rate
0.92%
 
0.97%
Expected dividend yield
2.46%
 
2.91%
Expected volatility
17.25%
 
16.20%
Expected term
3 years
 
3 years